   Unlike core pmap, it doesn't assume the buffer size is nprocessors + 2;
   instead, it tries to fill the pool."
   [pool f & colls]
-  (apply pmap-manual pool (impl/get-pool-size pool) f colls))
+  (apply pmap-manual pool nil f colls))
 
 (defn upmap-manual
   "Like pmap-manual, but with results returned in the order they completed.

  [pool & exprs]
  `(upcalls ~pool ~@(for [e exprs] `(fn [] ~e))))

(defmacro pfor
  "A parallel version of for. It is like for, except it takes a threadpool and
  is parallel. For more detail on its parallelism and on its threadpool

  background."
  [pool buffer-size f & colls]
  (let [[shutdown? pool] (impl/->threadpool pool)
        buffer-size (or buffer-size (impl/get-pool-size pool) 0)
        result-q (LinkedBlockingQueue. (int buffer-size))
        run-one (fn [a]
                  (let [p (promise)]
